Cross-linked ZnAl-LDH/PEDOT:PSS/MoS2 coating in-situ grown on aluminum alloy for excellent protection against both corrosion and wear

In this study, a new Al-LPM composite coating was in-situ deposited on the Al alloy via a facile one-pot hydrothermal method . Morphological and compositional characterizations revealed a tri-layered structure of the Al-LPM coating, namely, zinc aluminum-layered double hydroxide (ZnAl-LDH)/poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS)/MoS 2 . ZnAL-LDH was deposited closest to the surface of Al alloy , and the metallic ion-cross-linking of PEDOT:PSS makes the 3D coating more robust. The unique structure endows the coating with superior protective properties against both corrosion and wear. For anti-corrosion, the Al-LPM coating showed very high self-corrosion potential (-0.092 V) and small self-corrosion current density (46.0 μA cm −2 ) (vs. Al substrate with -1.157 V and 354.8 μA cm −2 , respectively), long-lasting high corrosion resistance (>57,000 Ω cm 2 ) during the immersion test, and the almost intact surface morphology and composition after 360 h corrosion. For anti-wear, the friction coefficient of the Al-LPM coating was determined to be < 0.2, which was much smaller than for the Al substrate (> 0.4). Also, there were no serious wear marks and grooves left after the dry-friction test.